US4227086A - Detectors of parameters adapted to act on the force of attraction between an electret and an electrode - Google Patents

Detectors of parameters adapted to act on the force of attraction between an electret and an electrode Download PDF

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Publication number
US4227086A
US4227086A US05/899,862 US89986278A US4227086A US 4227086 A US4227086 A US 4227086A US 89986278 A US89986278 A US 89986278A US 4227086 A US4227086 A US 4227086A
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Prior art keywords
electrode
electret
detection device
electrodes
parameter
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US05/899,862
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English (en)
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Gerard Dreyfus
Jacques Lewiner
Didier Perino
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H59/00—Electrostatic relays; Electro-adhesion relays
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
    • G01R19/16504—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values characterised by the components employed
    • G01R19/16514—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values characterised by the components employed using electronic tubes
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
    • G01R19/16566—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533
    • G01R19/16585—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533 for individual pulses, ripple or noise and other applications where timing or duration is of importance
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R5/00—Instruments for converting a single current or a single voltage into a mechanical displacement
    • G01R5/28—Electrostatic instruments
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
    • G01T1/00—Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
    • G01T1/02—Dosimeters
    • G01T1/14—Electrostatic dosimeters
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H59/00—Electrostatic relays; Electro-adhesion relays
    • H01H2059/009—Electrostatic relays; Electro-adhesion relays using permanently polarised dielectric layers

Definitions

  • ionizing radiation gamma rays, X-rays, neutrons . . .
  • ionizing radiation capable of progressively covering the charged face of the electret which is orientated towards the electrode A, with ions of the opposite polarity to that of said charge, so as to progressively neutralize the attractive effect of this charge on this electrode A
  • a predetermined difference in potential is applied between the two electrodes in such a manner as to pull these two electrodes towards one another and in particular to pull the electrode A against the electret.
  • the change in this difference in potential electrically controls the relative displacement of the electrode A in relation to the electret, this displacement being used for any desired purposes such as the closing or opening of an electric circuit, the release of the blocking of a fluid conduit, the deflection of a beam of light and the like.
  • the present invention again makes use of an assembly of the above type.
  • the two electrodes are connected to an assembly permitting selectively, (1) electrically connecting the electrodes together, or (2) the application of a difference in potential to the electrodes which causes movement (pivoting) of the movable electrode, or of a difference in potential opposed to the first potential difference applied between them being adapted to restore the movable electrode to its rest position after movement thereof,
  • the return means may comprise a mechanical spring.
  • the return means may comprise a permanent magnet.
  • a second electret is carried by the first electrode (electrode A) and faces the first electret with a face carrying charges of opposite sign to the sign of the charges carried by this first electret.
  • the invention comprises certain other provisions which are preferably used at the same time and which will be discussed more explicitly hereinafter.
  • FIG. 1 of this drawing shows, diagrammatically, a detector constructed according to the invention.
  • FIG. 2 shows, in vertical section, one embodiment of such a detector.
  • FIG. 3 shows, in perspective, with parts removed, another embodiment of such a detector.
  • One of the two electrodes namely the electrode A in the following description, is designed in such a manner as to be able to be displaced in relation to the electret E and hence in relation to the other electrode B under the action of return means when the electrostatic force of attraction exerted thereon by the electret becomes lower than the opposing force of these means as a result of the reduction in said force of attraction.
  • the two electrodes A and B always remain subject to the same electric potential and thus it is parameters other than the difference in electric potential between these two electrodes, which are capable of reducing, progressively or not, said force of attraction.
  • the invention is adapted to monitor the chosen parameter by detecting automatically the exceeding of a threshold by the parameter, the reduction in force in question being due either to a discharge of the electret or to a neutralization of its charges by supplying charges of the opposite sign.
  • displacements of the electrode A which occur responsive to such exceeding of the threshold, are used in any desirable manner i.e., in cooperation with electrical, magnetic, pneumatic, optical or other means capable, in particular, of lighting a luminous signal, of exciting a sound signal, of triggering a safety or correction operation.
  • the two electrodes A and B are permanently connected electrically to one another by a conductor wire 1 and that the only possible displacement of the electrode A is an angular displacement about a pin 2.
  • the return means have been represented by a helical tension spring 3.
  • the circuit for using the detector is an electrical circuit 4 controlled by a micro-switch 5 comprising a movable contact stud 6 carried by the electrode A and a fixed contact stud 7.
  • the intensity of the opposing return force F 2 due to the spring 3 is selected lower than that of F 1 .
  • the electrode A consists of a relatively rigid metal strip connected to its foot 8, which is embedded in a base 9, by a resiliently flexible region 10.
  • Region 10 may be a thinner or notched portion of the strip itself or may consist of an independent member.
  • the assembly consisting of the elements A, B, E, 9, 11, 12, is placed in a sealed bulb 13 from which there emerges four pins 14, 15, 16 and 17 electrically connected respectively to the electrodes A and B and to the contacts 6 and 7.
  • the electrical connection between the pin 16 and the contact 6 is ensured by means of a conductor path 18 applied in any desirable manner to the insulating layer 11.
  • This embodiment enables the electrical circuit containing the electrodes A and B to be insulated from that containing the contacts 6 and 7, which may have certain advantages as will be explained later on with reference to FIG. 4.
  • the embodiment shown diagrammatically in FIG. 3 enables the electret E to be replaced easily after operation of the detector, which is of interest when such a replacement is necessary between two successive operations of this detector.
  • the electrode B consists of a conductor frame. Stretched over this frame is a layer of metal such as a thin foil which constitutes the electret E. The frame is in electrical contact with this layer.
  • the electrode A is a conducting strip, the foot of which is fixed to the plate 20 by a belt-nut system 21.
  • the free end of this strip is disposed at the side of the foil E opposite to the frame electrode B and tends to move away resiliently from this foil to come into contact with the overhanging end of an arm of conducting metal constituting the fixed contact 7.
  • this electrode A is adapted in such a manner that the electrostatic attraction of the electret has the effect of applying it against the latter.
  • the foot of the electrode A is electrically connected by conductors 22, formed, for example, by the metal areas of a circuit printed on the plate 20, both to the frame electrode B and to a pin 23 which projects to the outside of a hermetic casing 13 surrounding the device.
  • Pin 23 here in this embodiment replaces all the pins 14, 15, 16 of the embodiment of FIG. 2.
  • the advantage of this embodiment lies in that the assembly of the frame B and of the foil E is mounted in such a manner as to be removed easily from the device once the casing 13 is removed.
  • this assembly is held pressed against the plate 20 by means of four resilient pincers 24 so that the assembly can slide between these pincers and the plate 20 for replacement.
  • the fixed electrode B may consist of any desirable material which is a conductor of electricity, such as solid brass.
  • the strip electrode A may advantageously consist of steel or of resilient bronze with a thickness between 10 and 500 microns.
  • the contact studs 6 and 7 may advantageously consist of gilded contacts or of contacts wetted with mercury or with a conducting grease.
  • the electret E it may advantageously be made from a foil or sheet of a polymer material selected from among the following: polyethylene, polypropylene, terephthalate of polyethylene, polytetrafluoroethylene, polycarbonate, halogenated polyhydrocarbide (for example a copolymer of hexafluoropropylene and tetrafluorethylene) polyvinylidene fluoride, a compound with a base of at least 95% of polychlorotrifluoroethylene, a compound with a base of polychlorotrifluoroethylene and polytetrafluoroethylene, a compound with a base of polyvinylidene fluoride and polytetrafluoroethylene, or a compound consisting of one of the preceding polymers with magnesia and polyacetal.
  • a polymer material selected from among the following: polyethylene, polypropylene, terephthalate of polyethylene, polytetrafluoroethylene, polycarbonate, hal
  • the thickness of the electret is preferably between 1,000 angstooms and 200 microns. Below 3 microns, it may be prepared, for example, by deposition under vacuum (cathodic atomization).
  • the electret may likewise consist of a mineral material (alumina for example) in which electric charges have been included, for example by electronic or ionic implantation or in which conducting elements have been included and charged.
  • a mineral material alumina for example
  • the phenomenon to be detected may be an ionizing radiation.
  • the radiation to be detected consists of neutrons
  • a layer of boron or of lithium may be deposited on the face of the electrode A facing the electret and thus constituting a target for the neutrons.
  • the charge given to the electret is a polarity opposite to that of the ions liable to be produced by the reaction of the neutrons to be detected with the target or the gas disposed close to the electret.
  • the ionizing radiation to be detected affects said face through the electret itself and/or one at least of the two electrode.
  • the radiation could affect the electrode B which then consists of a relatively thin layer of metal, or a metal (gold, aluminium) permeable to the particles to be detected, or a sheet of polymer constituting the electret.
  • FIG. 3 lends itself particularly well to a construction of this type.
  • any desirable screen may be provided around the detector in such a manner as to partially absorb some of the radiation of the environment in which it is situated.
  • a screen may, be an electrostatic screen consisting for example of the metal of the bulb 13 or of a grid or a cage, so long as it is capable of isolating the device from external electromagnetic parasites.
  • such a material as, for example, a compound with 10.2% of hydrogen (such as that comprising 66.1% of polyethylene, 11.1% of polyformaldehyde and 22.8% of magnesia) is suitable for neutrons, and a compound without hydrogen (such as that comprising 57% of polyetrafluorethylene (CF 2 -CF 2 ) n and 43% of carbon) is suitable for beta, gamma and X rays.
  • a compound with 10.2% of hydrogen such as that comprising 66.1% of polyethylene, 11.1% of polyformaldehyde and 22.8% of magnesia
  • a compound without hydrogen such as that comprising 57% of polyetrafluorethylene (CF 2 -CF 2 ) n and 43% of carbon
  • the phenomenon to be detected may likewise be the presence of a fluid capable of discharging the electret, said fluid consisting, in particular, of an organic vapor, or even of a liquid.
  • the fluid is brought into contact, in an adequate concentration, with the active face of this electret.
  • the phenomenon to be detected may also be temperature since the distribution of the electrical charges carried by an electret can be modified in time by heating it.
  • the means for urging the electrode A may be constituted in any desirable manner other than by an actual spring 3 as in FIG. 1 or by the inherent resilience of the base of a strip constituting this electrode as in FIGS. 2 and 3.
  • the two electrodes A and B may consist of the two legs of one and the same resilient metal strip folded into U-shape.
  • the curved base of this U then serves both as an electrical connecting member between the two electrodes A and B and as a resilient return member tending to part these electrodes from each other.
  • the electrode A may be urged to move away from the electret E by its own weight.
  • the electrode is then disposed below the electret and constituted or weighted in such a manner as to be sufficiently heavy.
  • a fixed permanent magnet is disposed opposite a magnetic or magnetizable region of this electrode at a distance from said region which can preferably be adjusted with precision by a screw adjustment.
  • This modification is a particular advantage since the magnetic attraction exerted by the magnet on the electrode A is inversely proportional to the square of the distance between this magnet and this electrode.
  • the electrode A may be left free to be displaced parallel to itself, possibly by means of a resilient support.
  • a resilient support for example, it could constitute of a pellet enclosed with slight peripheral play in a cylindrical or prismatic casing, one end of which consists of the electrode B covered with the electret E and the other end of which carries the contact stud 7 towards the inside of the casing.
  • the displacements of the electrode A may be transduced in a manner other than electrically.
  • these displacements can be used to block, release or deflect a luminous control beam, or to block or release an orifice of a pipe in which a control fluid is circulating.
  • such an embodiment a may utilize the displacements of the electrode A in ways other than by closing a circuit 4.
  • application of a movable contact permanently connected to one end of this circuit and carried by the electrode A against a fixed contact connected to the other end of said circuit would be suitable.
  • Such a circuit 4 may be closed by application of a movable bridge carried by the electrode A against two contacts themselves permanently connected to two ends of the circuit in question.
  • the displacement of the electrode A may likewise be used to open an electrical circuit instead of to close one. Or, the displacement could even be used to open one electric circuit and to close another at the same time, in the manner of a change-over switch.
  • a considerable advantage of the detection devices of the invention lies in that their operation does not require any inherent source of energy; the motive energy is, in fact, supplied in two ways.
  • this energy can be supplied by the phenomenon itself, for which it is intended to detect the exceeding of a threshold.
  • the energy can be supplied by the return means, the effect of which is released by exceeding the threshold.
  • the devices of the invention are particularly simple to manufacture and in operation, are inexpensive, light, and of small overall size.
  • the device in the event of accidental discharge of the electret, the device is automatically triggered and passes from its "watching" state to its "alarm” state.
  • FIG. 4 illustrates in full lines a complete portable detector assembly constructed by means of a device in accordance with FIG. 2 above, enclosed in a hermetic bulb 13 from which there emerge four pins 14, 15, 16 and 17.
  • the two pins 16 and 17 are connected in series with an electric battery 27 and an oscillator 28 which in turn feeds a small loud-speaker 29.
  • the two pins 14 and 15 are connected to one another.
  • the discharge of the battery 27 is practically nil in the watching state because it does not deliver any current, i.e., it only delivers a current in the case of an alert.
  • the two pins 14 and 15 are connected to a circuit 31. This will enable either of these two pins to be connected electrically to one another (position O of the diagrammatic index 32) or enable a positive direct voltage (position +) or a negative direct voltage (position -) to be applied between these two pins.
  • the device to be restored to its initial watching state, again by electrical control.
  • This succession of operations also enables the measurement of the dose of the parameter to be monitored which has been received by the device, even if this dose was not sufficient to trigger the device.
  • the dose is associated with the value of the direct voltage V which was required to ensure said triggering electrically.
  • Example 1 A detection device in accordance with FIGS. 2 and 4, comprising an electret of polypropylene 10 microns thick, enabled an alarm signal to be given for doses of X rays comprised between 100 mRem and 10 Rem and more, according to the charge of the electret and the resilient return force of the electrode A.
  • Example 2 A device of the type in Example B 1, but comprising an electret of 1 cm 2 in a copolymer of hexafluoropropylene and tetrafluorethylene 12.7 microns thick, placed at a distance of one centimeter from a source of cobalt 60, with an activity equal to 100 microcuries, enabled an alarm signal to be given at the end of a period of between 6 minutes and 10 hours, which corresponds to an exposure dose of between 0.13 and 13 R or a total absorbed dose of between 110 m Rad and 11 Rad.
  • Example 3 A device identical to that of example 2, placed in a drying oven enabled an alarm signal to be given about 24 hours after the temperature and reached 160° C.
  • the electret E is mounted on the movable electrode, which would then be the electrode B, the above-mentioned electrode A then being fixed and the return means which permanently urge this electrode A and the electret E towards mutual spacing then acting on the electrode B;

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Molecular Biology (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Measurement Of Radiation (AREA)
  • Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
  • Geophysics And Detection Of Objects (AREA)
  • Measuring Fluid Pressure (AREA)
  • Transmission And Conversion Of Sensor Element Output (AREA)
US05/899,862 1977-05-05 1978-04-25 Detectors of parameters adapted to act on the force of attraction between an electret and an electrode Expired - Lifetime US4227086A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR7713727 1977-05-05
FR7713727A FR2389896B1 (enrdf_load_stackoverflow) 1977-05-05 1977-05-05

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US4227086A true US4227086A (en) 1980-10-07

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US (1) US4227086A (enrdf_load_stackoverflow)
JP (1) JPS53141081A (enrdf_load_stackoverflow)
AR (1) AR215297A1 (enrdf_load_stackoverflow)
AU (1) AU3577878A (enrdf_load_stackoverflow)
BE (1) BE866731A (enrdf_load_stackoverflow)
BR (1) BR7802803A (enrdf_load_stackoverflow)
CA (1) CA1094231A (enrdf_load_stackoverflow)
DE (1) DE2819816A1 (enrdf_load_stackoverflow)
ES (1) ES469838A1 (enrdf_load_stackoverflow)
FR (1) FR2389896B1 (enrdf_load_stackoverflow)
GB (1) GB1601287A (enrdf_load_stackoverflow)
IL (1) IL54584A0 (enrdf_load_stackoverflow)
IT (1) IT1161397B (enrdf_load_stackoverflow)
NL (1) NL7804778A (enrdf_load_stackoverflow)
OA (1) OA05956A (enrdf_load_stackoverflow)
SE (1) SE425997B (enrdf_load_stackoverflow)
ZA (1) ZA782396B (enrdf_load_stackoverflow)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4320393A (en) * 1978-06-07 1982-03-16 Jean Engdahl Personal dosimeter with reminder time
US4355235A (en) * 1979-04-23 1982-10-19 Jacques Lewiner Devices for measuring parameters which can modify the charge of an electret
US4451736A (en) * 1982-04-16 1984-05-29 Wisconsin Alumni Research Foundation Method and apparatus for measuring air ion concentrations
US4988876A (en) * 1989-05-25 1991-01-29 Radon Testing Corporation Of America Personnel radiation dosimetry device and testing unit
US5002720A (en) * 1989-06-30 1991-03-26 The United States Of America As Represented By The Secretary Of The Air Force Electret enabled thermal neutron flux detection and measurement
US5055674A (en) * 1986-12-01 1991-10-08 Rad Elec, Inc. Electret ionization chamber for monitoring radium and dissolved radon in water
US5473683A (en) * 1992-02-13 1995-12-05 Northern Telecom Limited Post assembly process for adjusting the gain of an electret microphone within a communications apparatus
US20040263936A1 (en) * 2003-04-15 2004-12-30 Takeshi Nanjyo Optical deflection apparatus and manufacturing method thereof, optical deflection array, imaging apparatus, and image projection display apparatus
US8664827B2 (en) 2011-03-09 2014-03-04 Casio Computer Co., Ltd. Electric power generation device and electronic instrument
WO2014163946A1 (en) 2013-03-12 2014-10-09 Mirion Technologies, Inc. Radiation detector and method
US20200025956A1 (en) * 2016-08-14 2020-01-23 Nuclear Research Center Negev Neutron detector and method for its preparation

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2432236A1 (fr) * 1978-07-25 1980-02-22 Lewiner Jacques Perfectionnements aux disjoncteurs sensibles aux courants de fuites
FR2446490A1 (fr) * 1979-01-11 1980-08-08 Thomson Csf Dispositif de mesure integrale de radiations ionisantes
FR2455286A1 (fr) * 1979-04-23 1980-11-21 Dreyfus Gerard Perfectionnements aux dispositifs de mesure des parametres susceptibles de modifier la charge d'un electret
FR2475740A2 (fr) * 1980-02-11 1981-08-14 Lewiner Jacques Perfectionnements aux dispositifs de mesure de parametres susceptibles de modifier la charge d'un electret
FR2592722B1 (fr) * 1986-01-06 1988-05-06 Gonthier Bruno Procede de mesure de contamination et d'irradiation et capteur universel pour la mise en oeuvre dudit procede
KR102578823B1 (ko) * 2016-05-10 2023-09-15 삼성전자주식회사 마찰전기 발전기

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3436542A (en) * 1962-08-08 1969-04-01 Commissariat Energie Atomique Electrometer with automatic discharge
US3878496A (en) * 1971-06-14 1975-04-15 Us Energy Selectable level alarming personal dosimeter

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3436542A (en) * 1962-08-08 1969-04-01 Commissariat Energie Atomique Electrometer with automatic discharge
US3878496A (en) * 1971-06-14 1975-04-15 Us Energy Selectable level alarming personal dosimeter

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4320393A (en) * 1978-06-07 1982-03-16 Jean Engdahl Personal dosimeter with reminder time
US4355235A (en) * 1979-04-23 1982-10-19 Jacques Lewiner Devices for measuring parameters which can modify the charge of an electret
US4451736A (en) * 1982-04-16 1984-05-29 Wisconsin Alumni Research Foundation Method and apparatus for measuring air ion concentrations
US5055674A (en) * 1986-12-01 1991-10-08 Rad Elec, Inc. Electret ionization chamber for monitoring radium and dissolved radon in water
US4988876A (en) * 1989-05-25 1991-01-29 Radon Testing Corporation Of America Personnel radiation dosimetry device and testing unit
US5002720A (en) * 1989-06-30 1991-03-26 The United States Of America As Represented By The Secretary Of The Air Force Electret enabled thermal neutron flux detection and measurement
US5473683A (en) * 1992-02-13 1995-12-05 Northern Telecom Limited Post assembly process for adjusting the gain of an electret microphone within a communications apparatus
US20040263936A1 (en) * 2003-04-15 2004-12-30 Takeshi Nanjyo Optical deflection apparatus and manufacturing method thereof, optical deflection array, imaging apparatus, and image projection display apparatus
US7113321B2 (en) * 2003-04-15 2006-09-26 Ricoh Company, Ltd. Optical deflection apparatus and manufacturing method thereof, optical deflection array, imaging apparatus, and image projection display apparatus
US8664827B2 (en) 2011-03-09 2014-03-04 Casio Computer Co., Ltd. Electric power generation device and electronic instrument
WO2014163946A1 (en) 2013-03-12 2014-10-09 Mirion Technologies, Inc. Radiation detector and method
EP2984504A4 (en) * 2013-03-12 2016-11-09 Mirion Technologies Inc RADIATION DETECTOR AND METHOD
US9645256B2 (en) 2013-03-12 2017-05-09 Mirion Technologies Inc. Radiation detector and method
US20200025956A1 (en) * 2016-08-14 2020-01-23 Nuclear Research Center Negev Neutron detector and method for its preparation
US11002868B2 (en) * 2016-08-14 2021-05-11 Nuclear Research Center Negev Neutron detector and method for its preparation

Also Published As

Publication number Publication date
ES469838A1 (es) 1979-01-16
SE7805083L (sv) 1978-11-06
IT7809445A0 (it) 1978-05-04
AR215297A1 (es) 1979-09-28
ZA782396B (en) 1979-06-27
CA1094231A (en) 1981-01-20
NL7804778A (nl) 1978-11-07
IT1161397B (it) 1987-03-18
GB1601287A (en) 1981-10-28
BE866731A (fr) 1978-11-06
IL54584A0 (en) 1978-07-31
FR2389896A1 (enrdf_load_stackoverflow) 1978-12-01
BR7802803A (pt) 1979-01-02
DE2819816A1 (de) 1978-11-16
OA05956A (fr) 1981-06-30
FR2389896B1 (enrdf_load_stackoverflow) 1981-07-10
SE425997B (sv) 1982-11-29
AU3577878A (en) 1979-11-08
JPS53141081A (en) 1978-12-08

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